ACUTE AND SHORT-TERM HEMODYNAMIC, ECHOCARDIOGRAPHIC, AND CLINICAL EFFECTS OF ENALAPRIL MALEATE IN DOGS WITH NATURALLY ACQUIRED HEART-FAILURE - RESULTS OF THE INVASIVE MULTICENTER PROSPECTIVE VETERINARY EVALUATION OF ENALAPRIL STUDY

The efficacy of enalapril maleate in dogs with naturally acquired clas s III or class IV heart failure was evaluated in a multicenter study. Fifty-eight dogs with dilated cardiomyopathy (35 dogs), mitral regurgi tation (22 dogs), or aortic regurgitation (1 dog) receiving convention al therapy for heart failure (furosemide with or without digoxin) were included in a randomized double-blind study. Thirty-one dogs received enalapril tablets PO at approximately 0.5 mg/kg body weight bid, and 27 dogs received placebo tablets PO bid. Physical, electrocardiographi c. hemodynamic, echocardiographic, radiographic, and clinical examinat ions were performed on each dog before treatment and at the end of the approximately 21-day study. After treatment on day 0, the enalapril-t reated dogs had significantly (P<.05) lower heart rate, mean systemic arterial blood pressure, and mean pulmonary arterial blood pressure th an the placebo-treated dogs. Pulmonary capillary wedge pressure was ma rginally decreased (P=.0567) in the enalapril-treated dogs. When compa red with those in the placebo-treated dogs, scores for pulmonary edema were significantly (P<.05) decreased on day 2 in the enalapril-treate d dogs. At the end of the study, enalapril-treated dogs had significan tly (P<.05) greater decreases in class of heart failure, pulmonary ede ma score, and mobility score relative to baseline, and had significant ly (P<.05) better overall evaluation scores when compared with the pla cebo-treated dogs. This study shows the beneficial hemodynamic and cli nical effects of adding enalapril to conventional therapy for dogs wit h heart failure.